PIC16C65AT-20/PQ - 8-Bit 20MHz OTP MCU 7KB Flash | Microchip
MPN: PIC16C65AT-20/PQ β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.65 | $5.65 |
| 10 | $5.2 | $52.00 |
| 100 | $4.78 | $478.00 |
| 500 | $4.35 | $2,175.00 |
| 1,000 | $3.92 | $3,920.00 |
PIC16C65AT-20/PQ Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, non-volatile program memory, working RAM, and programmable I/O peripherals on one die. Within Microchip's portfolio, the PIC16C65AT-20/PQ sits in the mid-range PIC16 family - a tier above baseline PIC10/PIC12/PIC16 baseline parts and below the PIC17/PIC18 high-performance 8-bit families. As an OTP part, it is intended for cost-sensitive volume production where firmware is finalized before mask programming, replacing older ceramic-window EPROM PICs.
Key differentiating features include 33 programmable digital I/O pins, an enhanced 8-bit ADC with up to 8 channels, dual Capture/Compare/PWM (CCP) modules, a USART with addressable mode, an MSSP module supporting both SPI and I2C (master/slave), three timers (Timer0, Timer1, Timer2), and a programmable watchdog timer. The PIC16C65A revision fixes several silicon errata present on the original PIC16C65, particularly ADC acquisition timing and interrupt behavior. The part operates from 4.0 V to 6.0 V across the industrial -40 C to +85 C temperature range.
Typical applications include industrial control panels, motor drive control boards, HVAC controllers, embedded data acquisition systems, automotive body and chassis subsystems, and consumer appliance control. The wide peripheral set makes the part suitable for any system that needs analog sensing plus serial communication to a host. The 33 I/O count is generous for the era, allowing direct interface to keypads, displays, and parallel peripherals without external glue logic.
When designing with this part, note that OTP memory cannot be re-programmed - firmware must be fully validated on a windowed or flash sibling (PIC16F877 or PIC16F76) before committing to PIC16C65A production units. Decoupling VDD with 100 nF ceramic + 10 uF tantalum, plus a 10 MHz / 33 pF crystal on OSC1/OSC2, are mandatory per the datasheet typical-application circuit.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C65AT-20/PQ β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16C65AT-20/PQ (same form factor and footprint) β differing in Package, Program Memory Size, Program Memory Type, Timers, Mounting Type.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C65A-20/PQ
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65A-20I/PQ
β Drop-Inβ In Stock
$8.62 / Unit
View Datasheet βPIC16C65A-20E/PQ
β Drop-Inβ In Stock
$4.85 / Unit
View Datasheet βPIC16F877A-I/PQ
β Drop-Inπ Reference alternative (not in catalog)
PIC16F877-20/PQ
β Drop-Inπ Reference alternative (not in catalog)
PIC16C65A-10/PQ
β Drop-Inβ In Stock
$6.1 / Unit
View Datasheet βPIC16C65AT-20/PQ Maximum Ratings & Electrical Characteristics
| Family | PIC16C6X (mid-range 8-bit) |
| CPU Core | PIC16 RISC (Harvard) |
| Program Memory Type | OTP ROM |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 x 8 bytes |
| Data EEPROM | Not present (OTP family) |
| Maximum Clock Frequency | 20 MHz |
| Instruction Throughput | 5 MIPS (200 ns per instruction) |
| Operating Voltage (Vdd) | 4.0 V to 6.0 V |
| I/O Pins | 33 |
| ADC | 8-bit, 8 channels |
| Timers | 3 (Timer0, Timer1, Timer2) |
| CCP Modules | 2 |
| Serial Interfaces | USART, SPI, I2C (MSSP) |
| Package | 44-pin MQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (industrial) |
| Packaging Media | Tape & Reel (TR) |
| RoHS Status | Non-compliant (MQFP package, pre-RoHS era) |
| Silicon Revision | A (improved ADC & interrupt logic) |
PIC16C65AT-20/PQ Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (reset, active low) / Programming voltage input |
| Pin 2 | RA0/AN0 β PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 β PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 β PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF- β PORTA bit 3 / Analog input channel 3 / ADC Vref- |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / Analog input channel 4 / SPI Slave Select |
| Pin 8 | RE0/RD/AN5 β PORTE bit 0 / Parallel port Read control / Analog input 5 |
| Pin 9 | RE1/WR/AN6 β PORTE bit 1 / Parallel port Write control / Analog input 6 |
| Pin 10 | RE2/CS/AN7 β PORTE bit 2 / Parallel port Chip Select / Analog input 7 |
| Pin 11 | VDD β Positive supply voltage (+5V) |
| Pin 12 | VSS β Ground reference |
| Pin 13 | OSC1/CLKI β Oscillator crystal input / External clock input |
| Pin 14 | OSC2/CLKO β Oscillator crystal output / Clock output (Fosc/4) |
| Pin 15 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator input / CCP2 module |
| Pin 17 | RC2/CCP1 β PORTC bit 2 / CCP1 module (PWM/Capture/Compare) |
| Pin 18 | RC3/SCK/SCL β PORTC bit 3 / MSSP SPI clock / I2C clock |
| Pin 19 | RC4/SDI/SDA β PORTC bit 4 / MSSP SPI data in / I2C data |
| Pin 20 | RC5/SDO β PORTC bit 5 / MSSP SPI data out |
| Pin 21 | RC6/TX/CK β PORTC bit 6 / USART transmit / USART clock |
| Pin 22 | RC7/RX/DT β PORTC bit 7 / USART receive / USART data |
| Pin 23 | RB0/INT β PORTB bit 0 / External interrupt input |
| Pin 24 | RB1 β PORTB bit 1 |
| Pin 25 | RB2 β PORTB bit 2 |
| Pin 26 | RB3 β PORTB bit 3 |
| Pin 27 | RB4 β PORTB bit 4 |
| Pin 28 | RB5 β PORTB bit 5 |
| Pin 29 | RB6 β PORTB bit 6 |
| Pin 30 | RB7 β PORTB bit 7 |
| Pin 31 | VSS β Ground reference (second pad) |
| Pin 32 | VDD β Positive supply voltage (+5V, second pad) |
| Pin 33 | RD0 β PORTD bit 0 |
| Pin 34 | RD1 β PORTD bit 1 |
| Pin 35 | RD2 β PORTD bit 2 |
| Pin 36 | RD3 β PORTD bit 3 |
| Pin 37 | RD4 β PORTD bit 4 |
| Pin 38 | RD5 β PORTD bit 5 |
| Pin 39 | RD6 β PORTD bit 6 |
| Pin 40 | RD7 β PORTD bit 7 |
| Pin 41 | NC β Not connected (per datasheet) |
| Pin 42 | NC β Not connected (per datasheet) |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
PIC16C65AT-20/PQ is suitable for 6 applications: Industrial Control Panels, HVAC Climate Controllers, Motor Drive Control Boards, Embedded Data Acquisition Systems, Consumer Appliance Control, Automotive Body and Chassis Subsystems.
Industrial Control Panels
The PIC16C65AT-20/PQ fits industrial control panels where 33 GPIO, the 8-channel 8-bit ADC, and dual CCP (PWM) modules handle multi-loop sensing and actuator drive without external logic. The 5 MIPS instruction throughput at 20 MHz gives 200 ns deterministic cycle time for tight PID loops, while the USART connects to a host HMI or PLC link at 115200 baud. Industrial control designers value the PIC16C65A's hardened analog front-end over the original PIC16C65, particularly for 4-20 mA loop sensing with the on-chip ADC. Compared with switching to a flash-based PIC16F877A-I/PQ, the OTP part saves roughly 25% unit cost in 10K+ volumes when firmware is locked. Typical bill of materials around this MCU also includes a 4x4 keypad scan matrix, a 16x2 character LCD driven in 4-bit mode, and opto-isolated 24 V digital inputs on PORTB.
Recommended
HVAC Climate Controllers
The PIC16C65AT-20/PQ is a strong fit for HVAC climate controllers that need simultaneous temperature sensor reading, fan/blower PWM drive, and serial communication to a building automation bus. The 8-channel ADC handles multiple 10K NTC thermistor inputs on PORTA, while the two CCP modules generate PWM for variable-speed blower and damper control on PORTC. The MSSP module in I2C mode talks to an EEPROM for setpoint storage and a serial DAC for the temperature display, freeing the USART for BACnet or Modbus RTU communication with the building automation system. The 192-byte RAM is sufficient for HVAC scheduling state machines, and the 7 KB OTP program memory holds the full thermostat control algorithm. The OTP cost advantage versus flash PIC16F877A-I/PQ matters here because HVAC firmware changes rarely after release.
Recommended
Motor Drive Control Boards
The PIC16C65AT-20/PQ suits small brushless DC or stepper motor drive boards where its two CCP modules provide hardware PWM generation at up to 20 kHz switching frequency, and its 8-channel ADC samples phase current, back-EMF, and DC bus voltage simultaneously. At 5 MIPS throughput, the CPU can execute a sensorless BLDC commutation algorithm at 50 microsecond per electrical cycle while still servicing the USART for command input from a higher-level controller. The MSSP SPI peripheral drives a digital gate driver or resolver decoder at 5 MHz. Motor control designers appreciate the PIC16C65A's improved ADC acquisition timing over the original PIC16C65 (silicon errata fixed in revision A), which removes the need for external sample-and-hold circuitry. Drop-in compatibility with PIC16F877A-I/PQ allows iterative firmware tuning in flash before committing the final code to the cheaper OTP PIC16C65AT-20/PQ for production.
Recommended
Embedded Data Acquisition Systems
The PIC16C65AT-20/PQ is well-matched to embedded multi-channel data acquisition front-ends that read 8 analog inputs through its on-chip 8-bit ADC, store calibration parameters in an external I2C EEPROM via the MSSP, and stream samples over the USART to a host PC or logger. The 192-byte RAM supports a small 32-sample FIFO buffer for burst capture, while the 7 KB OTP program memory holds fixed binary-search calibration routines. Data acquisition designers value the PIC16C65A's deterministic ADC acquisition time (8 microseconds at 20 MHz), which allows precise timing of multiplexer switching. Compared to migrating to PIC18F or ATmega families, the PIC16C65AT-20/PQ keeps the BOM minimal - no external ADC, no external op-amp buffer for low-impedance sources, and a single 5 V supply rail.
Recommended
Consumer Appliance Control
The PIC16C65AT-20/PQ fits consumer appliance controllers (washing machines, dishwashers, microwave ovens, induction cooktops) where cost-optimized OTP memory reduces unit cost versus flash parts in high-volume production. The 33 I/O pins drive 7-segment displays, keypads, relay drivers, and triac control outputs simultaneously. The USART connects to an inverter board or sensor module, while the MSSP talks to an EEPROM for user preferences. The 8-channel ADC reads temperature sensors (NTC), water level sensors, and motor current. Compared to ATMEGA32A-AU alternatives, the PIC16C65AT-20/PQ costs roughly 30% less in 100K volumes because OTP eliminates flash test overhead. Drop-in compatibility with PIC16F877A-I/PQ allows the same PCB to be used for both development (flash) and production (OTP).
Recommended
Automotive Body and Chassis Subsystems
The PIC16C65AT-20/PQ is suitable for non-safety automotive body and chassis subsystems such as seat controllers, window regulators, mirror adjusters, and lighting controllers, where its 4.0-6.0 V supply tolerance accepts the noisy 12 V vehicle rail after a simple LDO. The 33 I/O pins drive multiple H-bridges and LED matrices, while the two CCP modules generate PWM for soft-start motor ramps. The PIC16C65A-20E/PQ extended-temperature variant (-40 C to +125 C) is preferred for under-hood or direct-sunlight environments. The MSSP SPI peripheral drives an external CAN transceiver companion chip for body-network connectivity, and the USART provides K-line diagnostic communication. Drop-in replacement with PIC16F877A-I/PQ is recommended for production designs that require in-circuit firmware updates.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C65AT-20/PQ β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C65A-20/PQ | PIC16C65A-20I/PQ | PIC16C65A-20E/PQ | PIC16F877A-I/PQ | PIC16F877-20/PQ | PIC16C65A-10/PQ |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same |
| Program Memory Type | OTP (7 KB) | OTP (7 KB) - identical | OTP (7 KB) - identical | OTP (7 KB) - identical | Flash (14 KB) | Flash (14 KB) | OTP (7 KB) - identical |
| Maximum Clock Frequency | 20 MHz | 20 MHz - identical | 20 MHz - identical | 20 MHz - identical | 20 MHz - identical | 20 MHz - identical | 10 MHz (-50%) |
| Operating Voltage | 4.0 V to 6.0 V | 4.0 V to 6.0 V - identical | 4.0 V to 6.0 V - identical | 4.0 V to 6.0 V - identical | 2.0 V to 5.5 V (wider) | 2.0 V to 5.5 V (wider) | 4.0 V to 6.0 V - identical |
| Operating Temperature | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) - identical | -40 C to +125 C (extended) | -40 C to +85 C (industrial) - identical | 0 C to +70 C (commercial) | 0 C to +70 C (commercial) |
| RAM Size | 192 x 8 bytes | 192 x 8 - identical | 192 x 8 - identical | 192 x 8 - identical | 368 x 8 (larger) | 368 x 8 (larger) | 192 x 8 - identical |
| ADC | 8-bit, 8 channels | 8-bit, 8 channels - identical | 8-bit, 8 channels - identical | 8-bit, 8 channels - identical | 10-bit, 8 channels (better) | 10-bit, 8 channels (better) | 8-bit, 8 channels - identical |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Active (recommended) | Active | Obsolete |
Key Differentiators
- OTP cost advantage in high-volume production (vs PIC16F877A-I/PQ)
- Silicon revision A fixes known errata (vs PIC16C65-20/PQ (original))
- Industrial temperature range option (vs PIC16C65A-20E/PQ)
Design Notes
The PIC16C65AT-20/PQ requires a single 4.0-6.0 V supply on VDD pins 11 and 32, with VSS pins 12 and 31 tied to ground. Per the Microchip datasheet (DS30234D) typical application circuit, place a 100 nF ceramic decoupling capacitor within 5 mm of each VDD pin plus a single 10 uF tantalum bulk capacitor on the supply rail. Brown-out reset is not enabled by default - configure the PCON register to enable it for reliable reset behavior in noisy industrial environments. The ADC VREF+ pin (if used) should be bypassed with 100 nF plus 10 uF.
The PIC16C65A is OTP (one-time programmable) - firmware cannot be rewritten. Develop and debug on a flash-based sibling (PIC16F877-I/PQ) which has an identical pinout and peripheral set, then burn the validated HEX file into the OTP PIC16C65AT-20/PQ using a PRO MATE II or PICSTART Plus programmer. Also note that in-circuit debugging (ICD) is NOT supported on PIC16C65A silicon - the ICD pins are not bonded out, so any firmware changes require a full device erase (impossible on OTP) and replacement. Plan firmware validation cycles carefully before committing to OTP volume.
At 20 MHz clock, the PIC16C65AT-20/PQ draws approximately 13 mA active current. With a 5 V supply, power dissipation is 65 mW in active mode. The MQFP-44 package has a thermal resistance of approximately 50 C/W, so a 65 mW dissipation yields a junction temperature rise of only 3.25 C above ambient - no heatsink required. In sleep mode the part draws less than 1 uA, making it suitable for battery-powered applications with duty-cycled wake-up.
The 44-pin MQFP package has a 0.8 mm lead pitch and 10x10 mm body. Per IPC-7351 nominal land pattern recommendations, the PCB footprint pads should be 1.0 mm wide x 0.4 mm long with a 1.6 mm pitch. Place a continuous ground pour on the top layer under the MCU body for thermal dissipation and EMI shielding. Route the OSC1/OSC2 clock traces as short as possible (under 10 mm) and guard them with a ground trace to minimize radiated EMI.
Compliance Information
The PIC16C65AT-20/PQ is a pre-RoHS-era MQFP-44 part using tin-lead (SnPb) lead finish and is NOT RoHS compliant. For RoHS-compliant production, migrate to PIC16F877A-I/PQ which uses lead-free finish. AEC-Q100 qualification is not applicable for this industrial-grade part.
